X-153862663-C-A

Variant names:

• chrX-153862663-C-A
• rs782235888
• NM_001278116.2:c.3774G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PM4

The NM_001278116.2(L1CAM):​c.3774G>T​(p.Ter1258Tyrext*?) variant causes a stop lost change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 24)
• Consequence: L1CAM NM_001278116.2 stop_lost
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.606
• Publications: 0 publications found

Genes affected

L1CAM (HGNC:6470): (L1 cell adhesion molecule) The protein encoded by this gene is an axonal glycoprotein belonging to the immunoglobulin supergene family. The ectodomain, consisting of several immunoglobulin-like domains and fibronectin-like repeats (type III), is linked via a single transmembrane sequence to a conserved cytoplasmic domain. This cell adhesion molecule plays an important role in nervous system development, including neuronal migration and differentiation. Mutations in the gene cause X-linked neurological syndromes known as CRASH (corpus callosum hypoplasia, retardation, aphasia, spastic paraplegia and hydrocephalus). Alternative splicing of this gene results in multiple transcript variants, some of which include an alternate exon that is considered to be specific to neurons. [provided by RefSeq, May 2013]

L1CAM Gene-Disease associations (from GenCC):

• L1 syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• X-linked hydrocephalus with stenosis of the aqueduct of Sylvius

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Genomics England PanelApp
• MASA syndrome

  Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• X-linked complicated corpus callosum dysgenesis

  Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• X-linked complicated spastic paraplegia type 1

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Stoplost variant in NM_001278116.2 Downstream stopcodon found after 98 codons.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001278116.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	L1CAM	NM_001278116.2	MANE Select	c.3774G>T	p.Ter1258Tyrext*?	stop_lost	Exon 29 of 29	NP_001265045.1	P32004-1
	L1CAM	NM_000425.5		c.3774G>T	p.Ter1258Tyrext*?	stop_lost	Exon 28 of 28	NP_000416.1	P32004-1
	L1CAM	NM_024003.3		c.3762G>T	p.Ter1254Tyrext*?	stop_lost	Exon 27 of 27	NP_076493.1	P32004-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	L1CAM	ENST00000370060.7	TSL:5 MANE Select	c.3774G>T	p.Ter1258Tyrext*?	stop_lost	Exon 29 of 29	ENSP00000359077.1	P32004-1
	L1CAM	ENST00000361699.8	TSL:1	c.3762G>T	p.Ter1254Tyrext*?	stop_lost	Exon 27 of 27	ENSP00000355380.4	P32004-2
	L1CAM	ENST00000361981.7	TSL:1	c.3747G>T	p.Ter1249Tyrext*?	stop_lost	Exon 26 of 26	ENSP00000354712.3	P32004-3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 24

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.48
CADD	Benign	10
DANN	Benign	0.85
FATHMM_MKL	Uncertain	0.89	D
PhyloP100		0.61
Vest4		0.25
GERP RS		3.9
Mutation Taster		=18/182	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs782235888; hg19: chrX-153128118;